- High-Yield Preparation of Exfoliated 1T-MoS2 with SERS Activity
-
Molybdenum disulfide (MoS2), a promising two-dimensional transition-metal dichalcogenide, presents a challenge in the tuning of its optoelectronic and chemical properties. Herein, we demonstrate an efficient route to alter the crystalline structure of MoS2 by chemical exfoliation. Using NaK metal alloys, exfoliated and covalently functionalized MoS2 derivatives were obtained with a high metallic (1T) phase ratio, up to 94.5%. Consequently, exfoliated MoS2 showed a significant surface-enhanced Raman scattering activity toward rhodamine 6G (R6G) and crystal violet, with low detection limits. The versatility of this approach allows the covalent functionalization of MoS2 without relying on edge or basal-plane defects of the structure and preserving the high-ratio 1T phase.
- Er, Engin,Hou, Hui-Lei,Criado, Alejandro,Langer, Judith,M?ller, Marco,Erk, Nevin,Liz-Marzán, Luis M.,Prato, Maurizio
-
-
Read Online
- A Radical Chain: Mononuclear “Gold Only” Photocatalysis
-
We herein report an unprecedented reactivity of mononuclear gold catalysts acting as classical catalysts and at the same time as active partners in a radical chain mechanism, whereby gold is the only catalyst. The mechanism of the photo-induced photosensitizer-free “gold only”-catalyzed cross coupling was studied in detail – experimentally and theoretically – based on the reaction between arylboronic acids and aryldiazonium salts. With a systematic set of stoichiometric experiments under various conditions and analytic methods, we could show that this mechanism is initiated by an aryl radical formed in the presence of blue LEDs and MeOH. This aryl radical enters the catalytic cycle to oxidize gold(I) to gold(II). Single electron transfer from gold(II) to the aryldiazonium salt then gives the cationic gold(III) complex by formation of a chain-supporting aryl radical which then is enabled to start a new cycle by oxidation of gold(I) without the need for irradiation. At least every 432 cycles of the radical chain, a new chain-initiating radical has to restart the radical chain. Eventually, the boronic acid is activated by the BF4? anion to transmetalate to gold(III), and reductive elimination delivers the desired product.
- Witzel, Sina,Hoffmann, Marvin,Rudolph, Matthias,Rominger, Frank,Dreuw, Andreas,Hashmi, A. Stephen K.
-
supporting information
p. 581 - 592
(2021/12/06)
-
- Aqueous and Visible-Light-Promoted C-H (Hetero)arylation of Uracil Derivatives with Diazoniums
-
Direct C5 (hetero)arylation of uracil and uridine substrates with (hetero)aryl diazonium salts under photoredox catalysis with blue light was reported. The coupling proceeds efficiently with diazonium salts and heterocycles in good functional group tolerance at room temperature in aqueous solution without transition-metal components. A plausible radical mechanism has been proposed.
- Liu, An-Di,Wang, Zhao-Li,Liu, Li,Cheng, Liang
-
p. 16434 - 16447
(2021/11/16)
-
- Metal-Free Visible-Light Synthesis of Arylsulfonyl Fluorides: Scope and Mechanism
-
The first metal-free procedure for the synthesis of arylsulfonyl fluorides is reported. Under organo-photoredox conditions, aryl diazonium salts react with a readily available SO2 source (DABSO) to afford the desired product through simple nucleophilic fluorination. The reaction tolerates the presence of both electron-rich and -poor aryls and demonstrated a broad functional group tolerance. To shed the light on the reaction mechanism, several experimental techniques were combined, including fluorescence, NMR, and EPR spectroscopy as well as DFT calculations.
- Chelagha, Aida,Khrouz, Lhoussain,Louvel, Dan,Monnereau, Cyrille,Payard, Pierre-Adrien,Rouillon, Jean,Tlili, Anis
-
supporting information
p. 8704 - 8708
(2021/05/17)
-
- Aryl Diazonium Salts: Powerful Arylating Agents for Catellani-Typeortho-Arylation
-
The Catellani reaction provides an efficient synthetic approach to polyfunctionalized arenes. However, the selectiveortho-arylating reagents employed in these reactions have been strictly limited to activated bromoarenes. As demonstrated in this work, aryl diazonium salts bearing both electron-donating and electron-withdrawing substituents, after in situ transformations with KI into the corresponding iodoarenes, were efficient arylating reagents for Catellani typeortho-arylation approaches.
- Fu, Ying,Guo, Liang-Liang,Zhang, Yu-Xia
-
supporting information
p. 17437 - 17444
(2021/12/02)
-
- HETEROARYLMETHYLENE DERIVATIVES AS DNA POLYMERASE THETA INHIBITORS
-
Disclosed herein are certain acetamido derivatives that are DNA Polymerase Theta (Polθ) inhibitors of Formula (I). Also, disclosed are pharmaceutical compositions comprising such compounds and methods of treating diseases treatable by inhibition of Polθ such as cancer, including homologous recombination (HR) deficient cancers.
- -
-
Paragraph 0243
(2020/08/22)
-
- RhIII-Catalyzed Synthesis of Highly Substituted 2-Pyridones using Fluorinated Diazomalonate
-
A RhIII-catalyzed strategy was developed for the rapid construction of highly substituted 2-pyridone scaffolds using α,β-unsaturated oximes and fluorinated diazomalonate. The reaction proceeds through direct, site-selective alkylation based on migratory insertion and subsequent cyclocondensation. A wide substrate scope with different functional groups was explored. The requirement of fluorinated diazomalonate was explored for this transformation. The developed methodology was further extended with the synthesis of the bioactive compound.
- Das, Debapratim,Sahoo, Gopal,Biswas, Aniruddha,Samanta, Rajarshi
-
supporting information
p. 360 - 364
(2020/01/25)
-
- Dual palladium-photoredox catalyzed chemoselective C-H arylation of phenylureas
-
A highly chemoselective C-H arylation of phenylureas has been accomplished using dual palladium-photoredox catalysis at room temperature without any additives, base or external oxidants. Regioselective C-H arylation ofN,N'-diaryl substituted unsymmetrical phenylureas has also been accomplished by a careful choice of aryl groups.
- Babu, Sakamuri Sarath,Shahid,Gopinath, Purushothaman
-
supporting information
p. 5985 - 5988
(2020/06/04)
-
- Visible-Light-Mediated Ru-Catalyzed Synthesis of 3-(Arylsulfonyl)but-3-enals via Coupling of α-Allenols with Diazonium Salts and Sulfur Dioxide
-
The first coupling of α-allenols, sulfur dioxide, and arenediazonium salts is presented. The three-component reaction which is promoted by visible light can be easily accomplished using DABSO as a sulfur dioxide surrogate in the presence of a photoredox catalyst. In this manner, a broad range of electron-rich and electron-deficient aryl substituents are well accommodated in the sulfonylation-rearrangement cascade to afford the 2,2-disubstituted 3-(arylsulfonyl)but-3-enals in reasonable yields. Based on control experiments, a radical mechanism which does imply 1,2-aryl migration has been proposed.
- Herrera, Fernando,Luna, Amparo,Almendros, Pedro
-
supporting information
p. 9490 - 9494
(2020/12/21)
-
- Discovery and structure-activity relationship studies of 1-aryl-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione derivatives as potent dual inhibitors of indoleamine 2,3-dioxygenase 1 (IDO1) and trytophan 2,3-dioxygenase (TDO)
-
Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO), which mediate kynurenine pathway of tryptophan degradation, have emerged as potential new targets in immunotherapy for treatment of cancer because of their critical role in immunosuppression in the tumor microenvironment. In this investigation, we report the structural optimization and structure-activity relationship studies of 1-phenyl-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione derivatives as a new class of IDO1/TDO dual inhibitors. Among all the obtained dual inhibitors, 1-(3-chloro-4-fluorophenyl)-6-fluoro-1H-naphtho[2,3-d][1,2,3]triazole-4,9-dione (38) displayed the most potent IDO1 and TDO inhibitory activities with IC50 (half-maximal inhibitory concentration) values of 5 nM for IDO1 and 4 nM for TDO. It turned out that compound 38 was not a PAINS compound. Compound 38 could efficiently inhibit the biofunction of IDO1 and TDO in intact cells. In LL2 (Lewis lung cancer) and Hepa1-6 (hepatic carcinoma) allograft mouse models, this compound also showed considerable in vivo anti-tumor activity and no obvious toxicity was observed. Therefore, 38 could be a good lead compound for cancer immunotherapy and deserving further investigation.
- Pan, Shulei,Zhou, Yangli,Wang, Qiusheng,Wang, Yanlin,Tian, Chenyu,Wang, Tianqi,Huang, Luyi,Nan, Jinshan,Li, Linli,Yang, Shengyong
-
-
- Heterogeneous visible-light-induced Meerwein hydration reaction of alkenes in water using mpg-C3N4 as a recyclable photocatalyst
-
A green and efficient visible light induced Meerwein hydration reaction of alkenes in aqueous medium using mpg-C3N4 as a recyclabe photocatalyst has been disclosed. This protocol provides a direct approach for the preparation of racemic alcohols via a free radical mechanism. Water acted as both a solvent and a reagent without any additives or co-solvents. The metal-free heterogeneous semiconductor is found to be fully recyclable at least 5 times without any significant reduction in activity. The Meerwein hydration reaction has an excellent substrate scope and gave the desired products in moderate to high yields. Furthermore, this reaction could be carried out under solar light irradiation and is applicable for large-scale reactions with satisfactory results.
- Wang, Jingjing,Xue, Linshuang,Hong, Mei,Ni, Bangqing,Niu, Tengfei
-
supporting information
p. 411 - 416
(2020/02/13)
-
- Fluorosulfonylation of arenediazonium tetrafluoroborates with Na2S2O5 and N-fluorobenzenesulfonimide
-
A transition-metal-free Sandmeyer-type fluorosulfonylation reaction has been achieved by the three-component reaction of arenediazonium tetrafluoroborates, Na2S2O5, and N-fluorobenzenesulfonimide (NFSI). The reaction proceeds through a radical tandem process, affording various arenesulfonyl fluorides in moderate to high yields. This protocol not only provides a complement to the previous fluorosulfonylation reactions, but also extends the applications of Sandmeyer reaction.
- Huang, Yangen,Liu, Shuai,Qing, Feng-Ling,Xu, Xiu-Hua
-
-
- Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C-H Functionalization of Indoles
-
Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C-H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.
- Guillemard, Lucas,Jacob, Nicolas,Wencel-Delord, Joanna
-
supporting information
p. 574 - 580
(2020/02/13)
-
- Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: Synthesis of: N -arylpyrazoles
-
A general method for the synthesis of structurally diverse N-arylpyrazoles from readily available cyclopropanols and aryldiazonium salts is disclosed. The reaction was conducted at room temperature within minutes with a broad substrate scope and excellent regioselectivity.
- Liu, Jidan,Xu, Erjie,Jiang, Jinyuan,Huang, Zeng,Zheng, Liyao,Liu, Zhao-Qing
-
supporting information
p. 2202 - 2205
(2020/02/26)
-
- Additions to N-Sulfinylamines as an Approach for the Metal-free Synthesis of Sulfonimidamides: O-Benzotriazolyl Sulfonimidates as Activated Intermediates
-
Sulfonimidamides are obtained in moderate to very good yields from the key intermediates O-benzotriazolyl sulfonimidates, which are formed by reacting aryldiazonium tetrafluoroborates, N-tritylsulfinylamine, and N-hydroxybenzotriazole hydrate in a process mediated by a tertiary amine. The formation of the sulfonimidate proceeds in inexpensive and environmentally benign dimethyl carbonate as the solvent, it does not require anhydrous conditions, and the product yields generally exceed 70 %. The substrate scope is broad, and a wide range of sensitive organic functionalities is well tolerated. The reactions probably proceed via aryl radicals formed from diazonium cations with assistance from both the tertiary amine and the sulfinylamine.
- Bremerich, Maximilian,Conrads, Christian M.,Langletz, Tim,Bolm, Carsten
-
supporting information
p. 19014 - 19020
(2019/11/22)
-
- Facile Synthesis of Tuneable Azophosphonium Salts
-
Azophosphonium salts have a facile synthesis and can be readily tuned at the para position of the aryl group and at the phosphorus position with the use of bulky phosphines, leading to a range of coloured compounds. A relation between the Hammett σ+para constant and the colour and 31P NMR chemical shift was explored. The compounds were characterised by NMR spectroscopy, UV/Vis spectroscopy and single-crystal X-ray structure crystallography.
- Habraken, Evi R. M.,van der Zee, Lars J. C.,van de Vrande, Koen N. A.,Jupp, Andrew R.,Nieger, Martin,Ehlers, Andreas W.,Slootweg, J. Chris
-
p. 1594 - 1603
(2019/02/09)
-
- Light-Induced Mechanistic Divergence in Gold(I) Catalysis: Revisiting the Reactivity of Diazonium Salts
-
In a systematic study of the Au-catalyzed reaction of o-alkynylphenols with aryldiazonium salts, we find that essentially the same reaction conditions lead to a change in mechanism when a light source is applied. If the reaction is carried out at room temperature using a AuI catalyst, the diazonium salt undergoes electrophilic deauration of a vinyl AuI intermediate and provides access to substituted azobenzofurans. If the reaction mixture is irradiated with blue LED light, C?C bond formation due to N2-extrusion from the diazonium salt is realized selectively, using the same starting materials without the need for an additional photo(redox) catalyst under aerobic conditions. We report a series of experiments demonstrating that the same vinyl AuI intermediate is capable of producing the observed products under photolytic and thermal conditions. The finding that a vinyl AuI complex can directly, without the need for an additional photo(redox) catalyst, result in C?C bond formation under photolytic conditions is contrary to the proposed mechanistic pathways suggested in the literature till date and highlights that the role of oxidation state changes in photoredox catalysis involving Au is thus far only poorly understood and may hold surprises for the future. Computational results indicate that photochemical activation can occur directly from a donor–acceptor complex formed between the vinyl AuI intermediate and the diazonium salt.
- Taschinski, Svenja,D?pp, René,Ackermann, Martin,Rominger, Frank,de Vries, Folkert,Menger, Maximilian F. S. J.,Rudolph, Matthias,Hashmi, A. Stephen K.,Klein, Johannes E. M. N.
-
supporting information
p. 16988 - 16993
(2019/11/13)
-
- Generation of 1,3-Dimethylene-Substituted Isobenzofurans via Pd(II)-Catalyzed Selective Oxo-cyclization/SO2 Insertion Cascade of β-Alkynyl Ketones
-
A new palladium(II)-catalyzed cyclization-radical addition cascade enables the direct construction of 1,3-dimethylene-substituted isobenzofuran derivatives containing a vinyl aryl sulfone unit in good yields by treating with β-alkynyl ketones, aryl diazonium salts, and DABCO·(SO2)2. The oxidant-free multicomponent reaction features good substrate scope and functional group tolerance, which proceeds through a sequence of Heck coupling, oxo-cyclization, and SO2 insertion.
- Liu, Shuai,Chen, Ke,Hao, Wen-Juan,Tu, Xing-Chao,Tu, Shu-Jiang,Jiang, Bo
-
p. 1964 - 1971
(2019/05/16)
-
- Preparation of N-Arylquinazolinium Salts via a Cascade Approach
-
An easy manipulation method for the preparation of N-arylquinazolinium salts is described from readily available aryldiazonium salts, nitriles, and 2-aminoarylketones in a one-pot operation. This method relies on the in situ generation of the N-arylnitrilium intermediate from the reaction of aryldiazonium salt with nitrile, which undergoes amination/cascade cyclization/aromatization, leading to N-arylquinazolinium salts in excellent yields. Nucleophilic addition of alkoxide to these N-arylquinazolinium salts provides functionalized dihydro-N-arylquinazoline.
- Ramanathan, Mani,Wan, Jing,Liu, Shiuh-Tzung
-
p. 7459 - 7467
(2019/06/14)
-
- Electrochemical Cross-Coupling of C(sp2)?H with Aryldiazonium Salts via a Paired Electrolysis: an Alternative to Visible Light Photoredox-Based Approach
-
Photoredox-based C?H bond functionalization constitutes one of the most powerful and atom-economical approaches to organic syntheses. During this type of reaction, single electron transfer takes place between the photocatalyst (PC) and redox- active substrates. Electrosynthesis also involves electron transfer between substrates and electrodes. In this paper, we focus upon electrochemical cross-coupling of C(sp2)?H with aryldiazonium salts and have developed an efficient electrochemical approach to the Minisci-type arylation reaction. The constant current paired electrosynthesis proceeds in a simple undivided cell without external supporting electrolyte, features a wide range of substrates and is easy to scale-up. These results demonstrate that photoredox-based cross-coupling of C(sp2)?H with aryldiazonium salts can also proceed successfully under paired electrolysis conditions, thereby contributing to understanding of the parallels between photosynthesis and electrosynthesis. (Figure presented.).
- Jiang, Yang-ye,Dou, Gui-yuan,Zhang, Luo-sha,Xu, Kun,Little, R. Daniel,Zeng, Cheng-chu
-
supporting information
p. 5170 - 5175
(2019/11/13)
-
- Cobalt bis(acetylacetonate)–tert-butyl hydroperoxide–triethyl-silane: A general reagent combination for the Markovnikov-selective hydrofunctionalization of alkenes by hydrogen atom transfer
-
We show that cobalt bis(acetylacetonate) [Co(acac)2], tert-butyl hydroperoxide (TBHP), and triethylsilane (Et3SiH) constitute an inexpensive, general, and practical reagent combination to initiate a broad range of Markovnikov-selective alkene hydrofunctionalization reactions. These transformations are believed to proceed by cobalt-mediated hydrogen atom transfer (HAT) to the alkene substrate, followed by interception of the resulting alkyl radical intermediate with a SOMOphile. In addition, we report the first reductive couplings of unactivated alkenes and aryldiazonium salts by an HAT pathway. The simplicity and generality of the Co(acac)2–TBHP–Et3SiH reagent combination suggests it as a useful starting point to develop HAT reactions in complex settings.
- Ma, Xiaoshen,Herzon, Seth B.
-
supporting information
p. 2259 - 2265
(2018/09/14)
-
- Palladium catalyzed stereocontrolled synthesis of C-aryl glycosides using glycals and arenediazonium salts at room temperature
-
A stereocontrolled synthesis of aryl-C-glycosides was achieved using glycals and aryldiazonium salts in the presence of palladium acetate. A wide range of glycals including d-glucal, d-galactal, l-rhamnal, d-xylal and d-ribal underwent C-arylation at the anomeric carbon in the presence of different aryldiazonium tetrafluoroborates and gave synthetically useful 2,3-deoxy-3-keto-α-aryl-C-glycosides in good to excellent yields. Broad substrate scope, simple operation and room temperature reactions make this protocol very attractive in organic synthesis.
- Singh, Adesh Kumar,Kandasamy, Jeyakumar
-
supporting information
p. 5107 - 5112
(2018/07/29)
-
- Synthesis of Chiral Sulfonyl Lactones via Copper-Catalyzed Asymmetric Radical Reaction of DABCO?(SO2)
-
In the present work, an asymmetric copper-catalyzed radical multi-component cascade reaction of an unsaturated carboxylic acid, aryldiazonium tetrafluoroborate, and DABCO?(SO2)2 (DABSO) has been developed for the enantioselective synthesis of sulfonyl lactones. In this reaction, this SO2 surrogate, DABSO was applied for the first time in the construction of chiral compounds. This multiple-step asymmetric radical reaction was carried out under mild conditions and tolerated a wide range of substrates, resulting in the corresponding sulfonyl lactones with up to 95% chemical yields and 88% ee. The current reaction enriches the research contents of DABSO, and provides a new and efficient strategy to chiral functionalized lactones bearing quarternary stereogenic center. (Figure presented.).
- Wang, Yang,Deng, Lingling,Zhou, Jie,Wang, Xiaochen,Mei, Haibo,Han, Jianlin,Pan, Yi
-
supporting information
p. 1060 - 1065
(2018/01/22)
-
- New transmetalation reagents for the gold-catalyzed visible light-enabled C(sp or sp2)-C(sp2) cross-coupling with aryldiazonium salts in the absence of a photosensitizer
-
The scope of photosensitizer-free visible light-driven gold-catalyzed cross-coupling was evaluated by a wide variety of organoboron and organosilicon species using four equivalents of aryldiazonium salts and (4-CF3-C6H4)3PAuCl in MeOH. In addition, a C(sp or sp2)-C(sp2) cross-coupling of organotrimethylsilanes and aryldiazonium salts was investigated. The reactions can be conducted under very mild reaction conditions, with a reduced amount of aryldiazonium salt (1.2 equiv.) by using a catalytic amount of Ph3PAuNTf2 in MeCN under irradiation with blue LEDs at room temperature.
- Witzel, Sina,Sekine, Kohei,Rudolph, Matthias,Hashmi, A. Stephen K.
-
supporting information
p. 13802 - 13804
(2018/12/14)
-
- Practical Reagents and Methods for Nucleophilic and Electrophilic Phosphorothiolations
-
New late-stage phosphorothiolation methods are disclosed that allow the efficient transfer of SP(O)(OR)2 groups to diversely functionalized substrates using nucleophilic and electrophilic reagents. The nucleophilic reagent, tetramethylammonium O,O-dimethyl phosphorothioate, was synthesized in near-quantitative yield from Me3SiP(O)(OMe)2, elemental sulfur and Me4NF. Its umpolung with N-bromophthalimide provided the electrophilic reagent, O,O-dimethyl-S-(N-phthalimido)phosphorothioate. Complementary methods based on these reagents enable the phosphorothiolation of diversely functionalized alkyl halides, arenediazonium salts, arylboronic acids and electron-rich arenes in good yields under mild conditions. (Figure presented.).
- Kovács, Szabolcs,Bayarmagnai, Bilguun,Aillerie, Alexandre,Goo?en, Lukas J.
-
supporting information
p. 1913 - 1918
(2018/03/30)
-
- An Iron-Based Long-Lived Catalyst for Direct C?H Arylation of Arenes and Heteroarenes
-
Direct C?H arylation of arenes and heteroarenes to biaryls at ambient temperature has been accomplished using a phenalenyl-supported iron(III) catalyst. The present catalyst requires a chemical reductant such as potassium and functions without any light stimulation. C?H arylation of various heteroarenes including pyridine as well as unactivated arene such as benzene delivered good to excellent yield (28 examples, up to 92 %) at room temperature. A combined effort based on experiments and theoretical calculations established that a phenalenyl-based radical species (generated by chemical reduction of the iron(III) coordinated phenalenyl complex) plays key role during the catalysis. Furthermore, this catalyst displayed remarkable stability during the catalysis, as evident from the fact that it was still usable over ten consecutive catalytic runs without losing its catalytic efficiency.
- Chakraborty, Soumi,Ahmed, Jasimuddin,Shaw, Bikash Kumar,Jose, Anex,Mandal, Swadhin K.
-
supporting information
p. 17651 - 17655
(2018/11/10)
-
- Visible-Light-Mediated Hydroxycarbonylation of Diazonium Salts
-
A visible light-promoted catalytic photoredox hydroxycarbonylation was achieved on aryl diazonium salts whether preformed or generated in situ from the corresponding anilines. This strategy allows a straightforward access to a variety of carboxylic acids under mild conditions. (Figure presented.).
- Gosset, Cyrille,Pellegrini, Sylvain,Jooris, Romain,Bousquet, Till,Pelinski, Lydie
-
supporting information
p. 3401 - 3405
(2018/08/06)
-
- Erythrosine B Catalyzed Visible-Light Photoredox Arylation–Cyclization of N-Alkyl-N-aryl-2-(trifluoromethyl)acrylamides to 3-(Trifluoromethyl)indolin-2-one Derivatives
-
3-Trifluoromethylindoline-2-one derivatives were prepared in a visible-light photocatalytic transformation of acrylamides. The arylation–cyclization sequence was initiated by light-induced aryl radical generation from aryldiazonium salts with the utilization of erythrosine B as an organic photocatalyst.
- Gonda, Zsombor,Béke, Ferenc,Tischler, Orsolya,Petró, Milán,Novák, Zoltán,Tóth, Balázs L.
-
supporting information
p. 2112 - 2117
(2017/04/24)
-
- Visible-Light-Promoted C-H Arylation by Merging Palladium Catalysis with Organic Photoredox Catalysis
-
The use of a dual palladium/organic photoredox catalytic system enables the directed arylation of arenes with aryldiazonium salts with a broad substrate scope at room temperature under mild reaction conditions. This study thus serves as not only an alternative route for the biaryl motifs but also a new example for the application of an organic photoredox catalyst.
- Jiang, Jian,Zhang, Wen-Man,Dai, Jian-Jun,Xu, Jun,Xu, Hua-Jian
-
p. 3622 - 3630
(2017/04/11)
-
- Visible-Light-Mediated Monoselective Ortho C-H Arylation of 6-Arylpurine Nucleosides with Diazonium Salts
-
A combined palladium- and photoredox-catalyzed monoselective arylation of 6-arylpurine nucleosides has been developed by employing purine as a directing group via the photoredox reaction, and many functional groups are well tolerated in this direct C-H arylation condition. Various of functionalized purines (nucleosides) which are potentially of great importance in medicinal chemistry could be obtained under visible light irradiation at room temperature within 4 h.
- Liang, Lei,Xie, Ming-Sheng,Wang, Hai-Xia,Niu, Hong-Ying,Qu, Gui-Rong,Guo, Hai-Ming
-
p. 5966 - 5973
(2017/06/07)
-
- Design and synthesis of photodissociable ligands based on azoimidazoles for light-driven coordination-induced spin state switching in homogeneous solution
-
Light-switchable azoimidazoles were rationally designed and synthesized, and their performance was investigated as photodissociable ligands (PDL) and for spin state switching of Ni porphyrins. The rationally designed ligands exhibit a high photochemical conversion rate (trans a? cis > 98%) and no measurable fatigue over a large number of switching cycles at room temperature under air. As compared to the known phenylazopyridines, the phenylazoimidazoles exhibit a much stronger affinity as axial ligands to Ni porphyrin in the binding trans configuration and a low affinity in their cis form. This affinity switching was used to control the coordination number of Ni2+. Concomitant with the change in coordination number is the change of the spin state from triplet (high spin) to singlet state (low spin). We report on phenylazoimidazole-based PDLs that switch the paramagnetic ratio of the investigated nickel species by up to 70%. Consequently, azoimidazoles exhibit considerably higher switching efficiencies than previously described pyridine-based PDLs.
- Schütt, Christian,Heitmann, Gernot,Wendler, Thore,Krahwinkel, Bahne,Herges, Rainer
-
supporting information
p. 1206 - 1215
(2016/02/18)
-
- Photosensitizer-Free Visible-Light-Mediated Gold-Catalyzed 1,2-Difunctionalization of Alkynes
-
Under visible-light irradiation, the gold-catalyzed intermolecular difunctionalization of alkynes with aryl diazonium salts in methanol affords a variety of α-aryl ketones in moderate to good yields. In contrast to previous reports on gold-catalyzed reactions that involve redox cycles, no external oxidants or photosensitizers are required. The reaction proceeds smoothly under mild reaction conditions and shows broad functional-group tolerance. Further applications of this method demonstrate the general applicability of the arylation of a vinyl gold intermediate instead of the commonly used protodemetalation step. This step provides facile access to functionalized products in one-pot processes. With a P,N-bidentate ligand, a stable aryl gold(III) species was obtained, which constitutes the first direct experimental evidence for the commonly postulated direct oxidative addition of an aryl diazonium salt to a pyridine phosphine gold(I) complex.
- Huang, Long,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
-
supporting information
p. 4808 - 4813
(2016/04/19)
-
- An unprecedentedly simple method of synthesis of aryl azides and 3-hydroxytriazenes
-
Fischer's approach towards the synthesis of aryl azides and triazinoles from diazonium salts and hydroxylammonium chloride (phenylhydraxylamine) was reinvestigated and optimized. The new methodology enables the preparation of aryl azides and triazinoles in high yields in water at room temperature. The procedure is very simple, robust, easily scalable, reproducible, and "green".
- Gribanov, Pavel S.,Topchiy, Maxim A.,Golenko, Yulia D.,Lichtenstein, Yana I.,Eshtukov, Artur V.,Terekhov, Vladimir E.,Asachenko, Andrey F.,Nechaev, Mikhail S.
-
supporting information
p. 5984 - 5988
(2018/06/06)
-
- The triple-bond metathesis of aryldiazonium salts: A prospect for dinitrogen cleavage
-
The {N2} unit of aryldiazonium salts undergoes unusually facile triple-bond metathesis on treatment with molybdenum or tungsten alkylidyne ate complexes endowed with triphenylsilanolate ligands. The reaction transforms the alkylidyne unit into a nitrile and the aryldiazonium entity into an imido ligand on the metal center, as unambiguously confirmed by X-ray structure analysis of two representative examples. A tungsten nitride ate complex is shown to react analogously. Since the bonding situation of an aryldiazonium salt is similar to that of metal complexes with end-on-bound dinitrogen, in which {N2}→M σ donation is dominant and electron back donation minimal, the metathesis described herein is thought to be a conceptually novel strategy toward dinitrogen cleavage devoid of any redox steps and, therefore, orthogonal to the established methods. Who knows? Although the extrusion of molecular nitrogen from aryldiazonium salts is extremely facile, the metathetic cleavage of the N-N triple bond on treatment with alkylidyne ate complexes of molybdenum or tungsten is shown to be even faster. The analogy between [Ar-N2]+ and known [M-N2] complexes makes this process a potential model for dinitrogen cleavage devoid of any redox steps.
- Lackner, Aaron D.,Fürstner, Alois
-
supporting information
p. 12814 - 12818
(2015/10/28)
-
- Ligand-Assisted Gold-Catalyzed Cross-Coupling with Aryldiazonium Salts: Redox Gold Catalysis without an External Oxidant
-
Gold-catalyzed C(sp)-C(sp2) and C(sp2)-C(sp2) cross-coupling reactions are accomplished with aryldiazonium salts as the coupling partner. With the assistance of bpy ligand, gold(I) species were oxidized to gold(III) by diazonium without any external oxidants. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the nitrogen extrusion followed by AuIII reductive elimination as the key step.
- Cai, Rong,Lu, Mei,Aguilera, Ellen Y.,Xi, Yumeng,Akhmedov, Novruz G.,Petersen, Jeffrey L.,Chen, Hao,Shi, Xiaodong
-
supporting information
p. 8772 - 8776
(2015/11/27)
-
- Cp?Ir(III)-Catalyzed Mild and Broad C-H Arylation of Arenes and Alkenes with Aryldiazonium Salts Leading to the External Oxidant-Free Approach
-
Reported herein is the development of Cp?Ir(III)-catalyzed direct C-H arylation of arenes and alkenes using aryldiazonium tetrafluoroborates, the use of which as an aryl precursor and also as an oxidant via C-N2 bond cleavage was a key to success in achieving a mild and external oxidant-free procedure. Mechanistic experiments and DFT calculations revealed the turnover-limiting step to be closely related to the formation of an Ir(V)-aryl intermediate rather than the presupposed C-H cleavage. Under the developed mild arylation conditions, a wide range of benzamides were smoothly arylated. In addition, synthetic utility of the current C-H arylation procedure was also demonstrated successfully for the (Z)-selective arylation of enamides and C8-selective reaction of quinoline N-oxides.
- Shin, Kwangmin,Park, Sung-Woo,Chang, Sukbok
-
supporting information
p. 8584 - 8592
(2015/07/15)
-
- Highly trans-Selective Arylation of Achmatowicz Rearrangement Products by Reductive γ-Deoxygenation and Heck-Matsuda Reaction: Asymmetric Total Synthesis of (-)-Musellarins A-C and Their Analogues
-
Fully functionalized pyranuloses derived from Achmatowicz rearrangement (AR) are versatile building blocks in organic synthesis. However, access to trans-2,6-dihydropyrans from pyranuloses remains underexplored. Herein, we report a new two-step trans arylation of AR products to access 2,6-trans-dihydropyranones. This new trans-arylation method built on numerous plausible, but unsuccessful, direct arylation reactions, including Ferrier-type and Tsuji-Trost-type reactions, was finally enabled by an unprecedented, highly regioselective γ-deoxygenation of AR products by using Zn/HOAc and a diastereoselective Heck-Matsuda coupling. The synthetic utility of the reaction was demonstrated in the first asymmetric total synthesis of (-)-musellarins A-C and 12 analogues in 11-12 steps. The brevity and efficiency of our synthetic route permitted preparation of enantiomerically pure musellarins and analogues (>20 mg) for preliminary cytotoxicity evaluation, which led us to identify two analogues with three-to-six times greater potency than the musellarins as promising new leads. O leaves, Ar comes: A highly regio- and diastereoselective trans-arylation of Achmatowicz rearrangement products by an unprecedented Zn-mediated reductive γ-deoxygenation and Heck-Matsuda reaction was developed for the efficient synthesis of trans-2-aryl-6-alkyl dihydropyranones (see scheme: L.A.=Lewis acid). The synthetic utility of this new method was further demonstrated in the first asymmetric total synthesis of (-)-musellarins A-C and 12 analogues in 11-12 steps.
- Li, Zhilong,Ip, Fanny C. F.,Ip, Nancy Y.,Tong, Rongbiao
-
supporting information
p. 11152 - 11157
(2015/11/10)
-
- One-Pot Reactions for Synthesis of 2,5-Substituted Tetrazoles from Aryldiazonium Salts and Amidines
-
One-pot sequential reactions of aryldiazonium salts with amidines followed by the treatment of I2/KI under basic conditions provide 2,5-disubstituted tetrazoles in moderate to excellent yields. This one-pot synthesis has several advantages such as mild reaction conditions, short reaction time, convenient workup, and high yields, making this methodology practical.
- Ramanathan, Mani,Wang, Yu-Hao,Liu, Shiuh-Tzung
-
supporting information
p. 5886 - 5889
(2015/12/11)
-
- An easy route to (hetero)arylboronic acids
-
An unprecedented spontaneous reactivity between diazonium salts and diboronic acid has been unveiled, leading to a versatile arylboronic acid synthesis directly from (hetero)arylamines. This fast reaction (35 min overall) tolerates a wide range of functional groups and is carried out under very mild conditions. The radical nature of the reaction mechanism has been investigated.
- Erb, William,Hellal, Akila,Albini, Mathieu,Rouden, Jacques,Blanchet, Jerome
-
supporting information
p. 6608 - 6612
(2014/06/09)
-
- Chiral anion phase transfer of aryldiazonium cations: An enantioselective synthesis of C3-diazenated pyrroloindolines
-
Herein is reported the first asymmetric utilization of aryldiazonium cations as a source of electrophilic nitrogen. This is achieved through a chiral anion phase-transfer pyrroloindolinization reaction that forms C3-diazenated pyrroloindolines from simple tryptamines and aryldiazonium tetrafluoroborates. The title compounds are obtained in up to 99% yield and 96% ee. The air- and water-tolerant reaction allows electronic and steric diversity of the aryldiazonium electrophile and the tryptamine core. Live and let diazene: Chiral anion phase transfer of aryldiazonium cations has been utilized to prepare C3-diazenated pyrroloindolines. The air- and water-tolerant reaction allows electronic and steric diversity in the aryldiazonium electrophile and the tryptamine core, with the products being obtained in up to 99% yield and 96% ee (MTBE=methyl tert-butyl ether).
- Nelson, Hosea M.,Reisberg, Solomon H.,Shunatona, Hunter P.,Patel, Jigar S.,Toste, F. Dean
-
supporting information
p. 5600 - 5603
(2014/06/10)
-
- A simple catalytic system based on PdCl2(CH3CN) 2 in water for cross-coupling reactions using diazonium salts
-
Aryl-heteroaryl and heteroaryl-heteroaryl compounds are obtained through the Suzuki-Miyaura cross-coupling reactions between diazonium salts and potassium trifluoroborates using PdCl2(CH3CN)2 as the catalyst in water and in the absence of any additive, ligand or base. In addition, the same mild catalytic system is effective for the Matsuda-Heck reaction between several monoolefins with aryldiazonium salts.
- El Bakouri, Ouissam,Fernández, Martí,Brun, Sandra,Pla-Quintana, Anna,Roglans, Anna
-
p. 9761 - 9765
(2013/10/22)
-
- Diazonium exchange and migration of pivaloyl group upon azo coupling of β-enaminones
-
4,4-Dimethyl-1-methylamino-1-phenyl-2-(substituted phenyldiazenyl)pent-1- en-3-ones (prepared upon azo coupling of 4,4-dimethyl-1-methylamino-1- phenylpent-1-en-3-one 6a with the corresponding benzenediazonium tetrafluoroborates) react with another molecule of substituted benzenediazonium tetrafluoroborate (in dichloromethane in the presence of anhydrous sodium acetate) to form substituted 4,4-bis(substituted phenyldiazenyl) derivatives 8. The second azo coupling is reversible. Derivatives 8 undergo either reverse cleavage of a diazonium ion or [1,3] sigmatropic rearrangement forming substituted formazane 9. In the case of the sequential use of two different diazonium tetrafluoroborates, the less electrophilic group splits off more easily. The structures of the products 9 were studied by means of X-ray, 1H, 13C, 19F and 15N NMR and MALDI HRMS analyses. The formazans 9 exhibit a reduced mobility of the phenyl group adjacent to the pivaloyl group, giving rise to anisochronism of proton and carbon atoms, to eventually form conformers. The reduced mobility was observed by means of NMR spectroscopy. A temperature dependence of the spectral behaviour was also studied. 4,4-Dimethyl-1-methylamino-1-phenyl-2-(substituted phenyldiazenyl)pent-1-en-3-ones react with benzenediazonium tetrafluoroborates through ipso attack, the products of which can undergo either migration of the pivaloyl group to form acylated formazans or reverse reaction to give the products of single azo coupling. With different diazonium salts an exchange of phenyldiazenyl groups is observed. Copyright
- Simunek, Petr,Bertolasi, Valerio,Machacek, Vladimir
-
p. 5683 - 5691
(2013/09/12)
-
- Deciphering DNA-based asymmetric catalysis through intramolecular Friedel-Crafts alkylations
-
We describe asymmetric intramolecular Friedel-Crafts alkylations with a DNA-based hybrid catalyst and propose a plausible binding model. This study shows promise for studying relationships between the helical chirality of DNA and enantioselectivity of the chemical reaction.
- Park, Soyoung,Ikehata, Keiichi,Watabe, Ryo,Hidaka, Yuta,Rajendran, Arivazhagan,Sugiyama, Hiroshi
-
supporting information
p. 10398 - 10400,3
(2020/09/09)
-
- Allylation and vinylation of aryl radicals generated from diazonium salts
-
(Chemical Equation Presented) Allylation and vinylation of aryl radicals generated from aryl diazonium salts provides rapid and efficient access to chlorinated and brominated derivatives of styrene and allylbenzene. Allyl chlorides were found to be better substrates than bromides due to decreased halogen transfer. Donor- and acceptor-substituted diazonium salts are well tolerated. The products represent important precursors for numerous further transformations.
- Heinrich, Markus R.,Blank, Olga,Ullrich, Daniela,Kirschstein, Marcel
-
p. 9609 - 9616
(2008/03/27)
-
- Sandmeyer reactions. Part 7.1 An investigation into the reduction steps of Sandmeyer hydroxylation and chlorination reactions
-
For Sandmeyer hydroxylation and chlorination in aqueous solution, the reduction steps have been investigated by means of correlation analyses of the effects of diazonium ion substitution on the rates of reduction. For simple hydroxylation, a change of behaviour between diazonium ions substituted by electron donor groups and those substituted by electron acceptor groups is interpreted as a change within an inner-sphere process from rate-determining electron transfer to rate-determining association of the reactants. By contrast, for citrate-promoted hydroxylation, a similar change in behaviour may be interpreted as a change between inner- and outer-sphere electron transfers. For chlorination, there is no mechanistic variation within the range of substituents examined but the pattern of behaviour is consistent with an inner-sphere mechanism. The various patterns of behaviour are rationalised in terms of the effects of diazonium ion substitution and catalyst ligation on the reduction potentials and self-exchange rates of the various reacting redox couples. Comparative correlation analyses of reductions and other electrophilic reactions of diazonium ions are used to support the arguments advanced in respect of Sandmeyer reduction steps. It is suggested that the Cu1 reductants react via a nucleophilic bridging ligand at the diazonium Nβ to give transient Z-adducts which are the precursor complexes and that activation for electron transfer involves rotation about the N-N bond.
- Hanson, Peter,Jones, Jason R.,Taylor, Alec B.,Walton, Paul H.,Timms, Allan W.
-
p. 1135 - 1150
(2007/10/03)
-
- Functionalization of carbon nanotubes by electrochemical reduction of aryl diazonium salts: A bucky paper electrode
-
Small-diameter (ca. 0.7 nm) single-wall carbon nanotubes are predicted to display enhanced reactivity relative to larger-diameter nanotubes due to increased curvature strain. The derivatization of these small-diameter nanotubes via electrochemical reduction of a variety of aryl diazonium salts is described. The estimated degree of functionalization is as high as one out of every 20 carbons in the nanotubes bearing a functionalized moiety. The functionalizing moieties can be removed by heating in an argon atmosphere. Nanotubes derivatized with a 4-tert-butylbenzene moiety were found to possess significantly improved solubility in organic solvents. Functionalization of the nanotubes with a molecular system that has exhibited switching and memory behavior is shown. This represents the marriage of wire-like nanotubes with molecular electronic devices.
- Bahr,Yang,Kosynkin,Bronikowski,Smalley,Tour
-
p. 6536 - 6542
(2007/10/03)
-
- Rates and mechanisms of the thermal solvolytic decomposition of arenediazonium ions
-
Arenediazonium tetrafluoroborates have been prepared and the kinetics of solvolysis have been investigated in water, trifluoroethanol, water-trifluoroethanol mixtures, hexafluoropropan-2-ol, trifluoroacetic acid, and ethanol by a UV method. A heterolytic mechanism involving short-lived aryl cations leads to products derived from nucleophilic capture of the aryl cations by solvent or a solute. Ionic solutes in aqueous trifluoroethanol and trifluoromethoxybenzene in trifluoroethanol have no kinetic effect and neither does replacement of the tetrafluoroborate counter-ion by chloride in trifluoroethanol. Rate constants for any one compound are not very solvent dependent, the reactions generally being characterised by high enthalpies of activation and appreciably positive entropies of activation. Compounds with 4-Cl, 4-F, 4-NO2, and 4-MeO substituents proved too unreactive for kinetic studies, but for different reasons. In ethanol, a radical reaction with characteristically different activation parameters competes with the heterolytic path and leads to hydrodediazoniation (reduction) by hydrogen atom abstraction from the CH2 group of ethanol.
- Canning, Peter S. J.,McCrudden, Katharine,Maskill, Howard,Sexton, Brian
-
p. 2735 - 2740
(2007/10/03)
-
- Process for preparing 2-(p-fluorophenyl)-2 methyl-propionic acid and 3-(p-fluorophenyl)-2-methylpropionic acid derivatives
-
Process for preparing 3-(p-fluorophenyl)-2-methylpropionic acid and derivatives thereof of the formula (I), STR1 in which R is a hydroxy group, a linear or branched (C1 -C8)-alkoxy group, an aryloxygroup, an amino group or a (C1
- -
-
-
- Influence of Steric and Electronic Effects on the Binding of Arenediazonium Cations to 18-Crown-6 in Methanol at 25 deg C
-
Log K, ΔH, and TΔS values for the interaction of several arenediazonium salts with 18-crown-6 were determined in methanol at 25 deg C by the calorimetric titration technique.The complex of benzenediazonium cation with 18-crown-6 is enthalpy stabilized with log K = 2.50.Substitution of a methyl group onto the ortho position(s) of benzenediazonium cation results in a total loss of complex stability.Substitution of various groups onto the para position results in changes in complex stability according to the electronic effect exerted in the diazonium moiety.A linear Hammett relationship (ρ = 0.65) was found between log K and ?+p values associated with the para substituent.
- Izatt, R. M.,Lamb, J. D.,Swain, C. S.,Christensen, J. J.,Haymore, Barry L.
-
p. 3032 - 3034
(2007/10/02)
-
- STUDIES OF CROWN ETHER COMPLEXES; ARYLDIAZONIUM ION COMPLEXES
-
DNMR studies show that for complexation of aryldiazonium salts 21-crown-7 is the preferred host.
- Krane, Jostein,Skjetne, Tore
-
p. 1775 - 1778
(2007/10/02)
-